This invention applies to the field of fiber optics, and more particularly spotlight luminaires, known as "pinspot" lights that produce a well collimated distribution of light with virtually no light outside an intense central beam; and wherein the beam may be zoomed to larger diameters.
A narrow, collimated beam requires the light-emitting end of a fiber optic light guide to be at the focus of a lens. If several fibers are used in a bundle to produce higher light levels the source image is larger, the resulting beam is also larger, but no brighter. Further, the individual fibers in the bundle are projected as a beam image of tube bundle, complete with the dark spots from the fiber interstices. For instance, if a bundle of five fibers is used, the projected beam will be Five adjacent circles of light, not a single, smoothly-illuminated circle. If a single, large "solid-core" fiber is used, the beam will be circular, but still will be the fiber image with characteristic fiber-cutting flaws clearly visible, and the larger area of the fiber will be projected as a lager beam, not a brighter one.
The primary purpose of the present invention is to provide a fiber optic light guide luminaire having a uniformly-illuminated beam from a number of fibers, wherein the intensity of the beam is increased as the number of fibers in increased; and wherein the beam has a very uniform intensity, without visible flaws or dark spots in the beam. This will permit the use of white, cold fiber optic illumination quality, without ultraviolet or infrared rays, in spotlight or downlight of sizes presently using MR-16, par-38 or par-56 lamps. The present invention will permit replacement of these relatively inefficient incandescent parlamp or miniature halogen lamps luminaires that produce poor quality light.